An admin pauses and resumes a webhook from the terminal's webhook list with `p`, and a paused hook gets no deliveries #8082

Intent: when an endpoint is down for a while, the owner pauses its hook instead of deleting it and losing its URL and secret. The webhook.active column exists and enqueueForEvent already skips inactive hooks, but nothing can set it.

Done looks like:

• [ ] src/core/webhooks.ts gains setWebhookActive(db, repoId, hookId, active), answering false for a hook of another repository; Webhook carries active.
• [ ] The terminal's webhook list (src/tui/screens/hooks.ts, the list screen — not the Deliveries screen) offers p "pause" / "resume" on the selected hook to whoever may manage it (the screen's existing gate); a paused row reads paused in place of its last delivery; the change is an event (webhook.paused / webhook.resumed) on the bus as other hook changes are.
• [ ] A paused hook receives nothing for events while paused; on resume new events are delivered again (nothing is backfilled).
• [ ] Tests: test/webhooks.test.ts proves a paused hook enqueues nothing and resumes; test/tui-hooks.test.ts drives p twice. Each fails without the change.

Files: src/core/webhooks.ts, src/tui/screens/hooks.ts, test/webhooks.test.ts, test/tui-hooks.test.ts

Risks: #8075 also edits src/core/webhooks.ts and the Deliveries screen in hooks.ts; keep to the list screen and a new function so the two merge cleanly, rebasing on whichever lands first. Leave API/MCP (hot) alone.

Brief: scout or mason.

Parked by the crew: the check stayed red through 2 automatic tries: MCP backups > a listing that fails is a short sentence with no key in it (pull #8088 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.